Simplify the following expression: $n = \dfrac{-4y + 9}{8y + 2} - \dfrac{-9y + 18}{8y + 2}$
Solution: Since the expressions have the same denominator we simply subtract the numerators: $n = \dfrac{-4y + 9 - (-9y + 18)}{8y + 2}$ Distribute the negative sign: $n = \dfrac{-4y + 9 + 9y - 18}{8y + 2}$ Combine like terms: $n = \dfrac{5y - 9}{8y + 2}$